Gilera Nexus 500 Workshop Manual page 280

Injection
1 electronic control unit
2 Valve position sensor
3 Air temperature sensor
4 Fluid temperature sensor
The throttle valve position sensor is not removable
and is installed on the throttle body.
This sensor receives a 5-V power supply from the
control unit and transmit a gradually increasing
voltage to the same, with an increase of the throttle
valve opening. The control unit converts this volt-
age at an angular position of the valve.
The engine rpm and the throttle valve position are
the two basic signals for the engine management.
A failure of this circuit causes the switching on of
the injection indicator and the tripping of the safe-
ties. In these conditions, the engine works, even
though not in an optimum way, always safeguard-
ing the catalytic converter integrity.
The throttle valve position signal is especially im-
portant at the small valve openings. These areas
are also where the sensor works more frequently,
and therefore they require more frequent checks
after a high number of kilometres run.
To check the sensor and related circuit, proceed
as follows:
1 - Connect the diagnostic tester.
Set the switch to "ON" with switch to "RUN" and
side stand raised.
Select the tester menu on the «ERRORS» func-
tion.
Check whether the control unit has detected any
failures relating to the throttle valve position signal.
YES go to 6 NO go to 2
Specific tooling
020460Y Scooter diagnosis and tester
INJEC - 88
CIRCUIT LAYOUT
Specification
Nexus 500
Desc./Quantity